A first conventional optical fiber array comprises optical fibers arranged in an array between a substrate and a pressing plate, wherein the optical fibers are positioned in V-grooves on the substrate to be extended out of a tape fiber. Such optical fiber arrays are fixed to be connected by adhesive, such that the optical fibers are optically aligned at facing ends of corresponding optical fibers.
A second conventional optical fiber array comprises a resin molded ferrule in which optical fibers are arranged in an array to be extended out of a tape fiber. In connecting the optical fiber arrays, male and female ferrules are prepared to be optically connected in accordance with the assistance of guide pins to provide the axial alignment of the optical fibers between the male and female ferrules.
In the first conventional optical fiber array, however, there is a disadvantage in that manual operation takes a long time to provide the optical axial alignment of the optical fibers which is carried out by placing the optical fiber arrays on a finely moving mount. When the finely moving mount is replaced by an automatical alignment apparatus, cost is increased due to high price of the automatical alignment apparatus.
In the second conventional optical fiber array, there is a disadvantage in that connecting operation is troublesome, because the guide pins which are separated from the ferrules are used. If the guide pins are fixed to one of the male and female ferrules, it becomes difficult to clean the end surfaces of the optical fibers.
In order to overcome these disadvantages in the first and second conventional optical fiber arrays, the inventors have proposed first and second optical fiber array structures in which adapters having guide apertures are used.
In the first proposed optical fiber array structure, the V-groove substrate and the pressing plate in the first conventional optical fiber array are made by zirconia.
However, the precision of a thickness and a width of the optical fiber array having a cross-section of rectangle is limited to .+-.5 .mu.m.
In the second proposed optical fiber array structure, the cross-section of the first proposed optical fiber array is changed to be circular, because the circular shape is easier in fabrication to increase the precision of the optical axial alignment.
However, the circular optical fiber array is rotated in a circular guide aperture of the adapter to lower the precision of the optical axial alignment.